Rocky fights a man named Spider Rico in the movie's first scene. It shows us Rocky's passionate, if less than elegant, fighting style. Rocky doesn't do much until Rico headbutts Rocky, almost breaking his precious nose, and Rocky takes revenge. Also, we had to mention this because "Spider Rico" is a pretty freaking amazing name.
Later in the movie, Rocky walks a neighborhood girl named Marie home. He lectures her on reputation, not wanting her to be known as a "whore." She thanks him by saying, "Screw you, creep-o!" And the next time Rocky sees her with her little gang, he ignores her. She breaks his self-esteem, and makes him think that he can't do any good, no matter how hard he tries. Marie actually appears again thirty years later in the 2006 film Rocky Balboa.
Finally, there's Jergens, the boxing promoter named after a moisturizer. (He's so slick, maybe the moisturizer is named after him.) Always dressed as a dandy, complete with red carnation, he's like the white Don King to Apollo's Mike Tyson. He orchestrates the fight with Rocky, and does very little else. That's okay, though: he's a flat character intended to provide us exposition and move the plot along to the big fight.